This invention relates generally to wheel assemblies for toy vehicles and particularly to a wheel that expands when accelerated or run at a high rate of speed.
Wheel extensions and expandable wheels of various types are known that provide added traction or wheel diameter to overcome obstacles or to simply change the appearance of the vehicle. To extend projections from the wheels or expand the diameter of the wheel itself, actuators were used that include gear mechanisms or camming means such as those disclosed in U.S. Pat. Nos. 4,773,889 and 4,601,519. Thus, it is desirable to have a wheel that expands when little or no resistance is applied to the vehicle or wheel assembly and without a complicated mechanism to effect the change.